We already mentioned in Sect.  that [1]} suggested that FGs are only a transitional phase in the life of a regular group/cluster. They claimed that this phase would happen just after a major merger and before other bright galaxies are accreted to the group. An example of such a process is found in [2]}: the Cheshire Cat galaxy group is formed by two smaller groups, dominated by one bright galaxy each. These groups are experiencing a line-of-sight merger that will end up in approximately one Gyr with the merging of the two structures. The authors suggested that the resulting structure will be a massive fossil group, dominated by a large \(M_r = -24\)  galaxy.
